/* 精准还原图像展开速度 */
.dropdown-list {
  transition: 
    opacity 0.3s ease-out,
    transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  transform-origin: top center;
}

/* 展开动画 */
.dropdown-list-active {
  opacity: 1;
  transform: scaleY(1);
}

/* 收起动画 */
.dropdown-list-inactive {
  opacity: 0;
  transform: scaleY(0.95);
}